This invention relates generally to integrated circuit components and, more particularly, to integrated circuit components adapted for use in digital systems.
As is known in the art, digital apparatus is generally made up for a number of interconnected integrated circuit components, such as, for example, counter, shift/storage registers, decoders/multiplexers, read only memories, random access memories, arithmetic units and microprocessors. These components are generally affixable to socket type connectors, such connectors being interconnected by a printed circuit board. One of the components, the decoder/multiplexer, is generally used to route binary input signals coupled to the input ports of such component to selected output ports of the component selectively in accordance with a control signal fed to the component. That is, for a particular decoder/multiplexer, a fixed predetermined relationship exists between the control signals and the manner of routing the input signals to the output ports. If it is necessary to change the relationship, that is, route the input signals to different output ports in response to the same control signals, then rewiring of the printed circuit board is required and such is a relatively expensive process.
As is also known in the art, another integrated circuit component, the programmable read only memory (PROM), includes a programmable diode matrix fed by a decoder to address each row of the matrix. That is, each row of the matrix corresponds to a memory address, such row or address being programmed to store a digital word. The memory is addressed by a digital word which is fed to the decoder. The decoder, in response to such digital word, enables or selects a corresponding one of the rows of the matrix which is then read from the memory. While such integrated circuit component has been found satisfactory for use as a memory, such component is not practical for routing input signals described above because, for example, if it is desired to selectively route ten input signals over one thousand rows would be required for the matrix. Further, because the decoder includes pairs of inverters for producing "true" and "complement" signals, erroneous transient signals, sometimes referred to as glitches, may be produced when the component is required to operate with high input data rates because the "true" and "complement" signals do not switch simultaneously.